The present invention relates to a structure by which an automatic document feeder (hereinafter, referred to as ADF) is installed to a copying apparatus.
In conventional copying apparatus, when a plurality of documents are copied, it is inefficient to put the document on a document exposure portion one sheet by one sheet. Therefore, the ADF by which the document is automatically fed to the exposure portion, is used. The ADF is inefficient when one sheet of document is copied, and in this case, it is better that the ADF is lifted up, and the document is directly put on a platen glass of the document exposure portion. Therefore, the ADF is frequently lifted up or closed depending on the number of document sheets. Generally, the ADF has a belt to feed documents, rollers, a driving source, and the like therein, and its weight is about 7 to 10 Kg. The ADF is pivotally provided to the apparatus either at one side, and the other side is lifted, or at the rear side, and the front side is lifted. The ADF, whose weight is 7 to 10 kg as described above, is a device by which a document is fed to the exposure portion, and therefore, it is inevitably fixed directly to a frame of an optical system. The frame of the optical system is separately manufactured from a main body of the apparatus for the purpose of providing a platen glass, a moving exposure lamp, reflector mirrors, and a lens thereto, and since a driving means for the exposure lamp and reflector mirrors must be provided to its sides, cut-out portions or the like are provided thereon. The platen glass, the exposure lamp, and the reflector mirrors are accurately provided to the optical frame manufactured separately, and since it is structured so that a document image can be exposed and a latent image can be formed on an image carrier, distortion of the optical path may be caused when the optical frame is deformed by external force, so that an accurate latent image cannot be formed. When the ADF is directly provided to the optical frame as described above, bending moment, or oscillation can occur at the portion where the ADF is pivotally provided, and is transmitted to the optical frame when the ADF is opened and closed forcibly, a portion or all of the optical frame can be deformed, and thus the optical path is distorted as described above, and accurate image formation can not be performed.